1665005005 has 4 divisors (see below), whose sum is σ = 1998006012. Its totient is φ = 1332004000.

The previous prime is 1665004997. The next prime is 1665005047. The reversal of 1665005005 is 5005005661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5005005661 = 269 ⋅18605969.

It can be written as a sum of positive squares in 2 ways, for example, as 553049289 + 1111955716 = 23517^2 + 33346^2 .

It is not a de Polignac number, because 1665005005 - 2³ = 1665004997 is a prime.

It is a Duffinian number.

1665005005 is a modest number, since divided by 5005 gives 1665 as remainder.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 166500496 + ... + 166500505.

It is an arithmetic number, because the mean of its divisors is an integer number (499501503).

Almost surely, 2^1665005005 is an apocalyptic number.

It is an amenable number.

1665005005 is a deficient number, since it is larger than the sum of its proper divisors (333001007).

1665005005 is an equidigital number, since it uses as much as digits as its factorization.

1665005005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 333001006.

The product of its (nonzero) digits is 4500, while the sum is 28.

The square root of 1665005005 is about 40804.4728553133. The cubic root of 1665005005 is about 1185.2369469269.

The spelling of 1665005005 in words is "one billion, six hundred sixty-five million, five thousand, five".